mod_log_json: Prefer native Lua table.pack over Prosody util.table one Prosody is removing support for Lua 5.1, which was the reason for util.table.pack to exist in the first place, since Lua 5.2+ provides table.pack. In prosody rev 5eaf77114fdb everything was switched over to use table.pack, opening the door for removing util.table.pack at some point. This change here is to prepare for that future eventuality.

# Introduction

This module sends a [version query][xep0092] to clients when they
connect, and logs the response, allowing statistics of client usage to
be recorded.

Note that since this is per connection, there will be a bias towards
mobile clients on bad connections.

## Example

    info    Running Running Swift version 4.0